Process of curving printing plates



Oct. 23, 1928. I 1,688,648

E. E. NOVOTNY PROCESS OF CURVING PRINTING PLATES Original Filed 1926 m c I V 7 9V A Q /L 30 Patented Oct. 23,1928.

UNITED STATES man. a. NOVOTNY, or PHILADELPHIA, rannsnvanm, Assmnoa 'ro Jonns'ro'e- DELL STOKES, 01 SPRING VALLEY. FARMS, 'HUN' IINGTON PENNSYLVANIA.

VALLEY rosaror'rrcn',

success or convme rnmrme rna'rns.

Original application filed February 9, 1926,'S er1a1 No. 87,111. Divided and thin application filed I 7 November 19, 1928.

This inventionrelatesto a 'processof producing curved printing plates. The method is particularly directed to the curving of a particular type of printing plate wherein the printing plate comprises a special, nonhomogeneous sprayed metal having great thermoplasticity.

The present application is a divislon of my copending application, Serial No. 87,111, filed February 9, 1926, for printing plate and method of making the same.

Briefly stated, my method is directed to the curving of metallic printing plates formed through the action of a metallic spray so adjusted that a porous, non-homogeneous structure will be produced. This printing plate body, because of its lack of homogeneous qualities, is capable of being rendered thermoplastic by being heated to a temperature well below its melting po1nt and may therefore be curved by merely being heated upon a suitable mandrel, the weight of the printing plate itselfbeing suflicient for this purpose. This great thermoplasticity a temperature well below its melting point per mits of curving metalhc printing plates or printing plates comprising a metalhc body without undue distortion and results 1n a true curve which will cling to the cylinder of the press throughout its area. A slight pressure, however, is most desirable and therefore I prefer to produce the curving under the combined action of heat and pressure. By applying pressure and providing a suitably curved form the printing plate may at the same time be leveled or have the makeready incorporated therein during the act of curving the same. The process therefore makes possible the curving of plates with a minimum amount of distortion and permits at the same time the introduction of the regu-' larities and irregularities required for high grade printing. This is an advantage not only from the standpoint of saving 1n operations but at the same time insures that a plate having been leveled at the time that it is curved will not have such leveling or makeready distorted or destroyed because of a subsequent curving operation. My copending application, Serial No. 149,452 filed November 19, 1926, for process of correcting printing plates, which is also a division of my copending application Serial No. 87,111,

Serial 110. 149,468.

filedFebruary 9, 1926, claims specifically the leveling operation. 7

After long experimentation'with eutectic alloys in the form of foil and plastic metal, I have discovered that an alloy such as foun dry type, monotype, or similarmetals including various alloys comprising metals such as lead, tin and antimony, is most useful for my purpose. These alloys when applied to a suit-able original by means of a metalhc spray properly adjusted form a structure which is not homogeneous, and the particles are therefore combined in a structure having a smooth, clean, polished workmg face but a body of more or less open porous structure. The particles upon striking thesurface of a properly repared matrix deposit thereon Without rebounding therefrom and form small, thin, scalelike portions, Y

apparently having oxidized faces, the oxide or perhaps the coolin of the thin sections preventing the formatlon of a solid homoge neous welded body. Apparently, too, where alloys are used, certain of the lowest melting components, such as the eutectic alloys of the composition, are thrown out to the edges and these tend to hold the structure in form, with the addition, however, of a certain intermeshmg or commingling of the odd'size particles of the spray. Be that as it may, however, actual experimentation has proven that these non-homogeneous plates, whether made of an alloy or of a solid metal but so long as they are sprayed in an open no-homogeneous manner, will display remarkable thermoplastic properties. This is very Well covered in my copendingapplication previously referred to, Serial No. 87,111, filed February 9, 1926.

Even though the printing plate should have a relatively tough facing section formed by depositing harder metals either by means of the spray or by means of an electrolytic deposit, the body portion when made by my spray method will still retain its thermoplastic properties, and therefore it is not essential that the printing plate be made entirely of non-homogeneous material as it may be a composite structure.

This composite structure may comprise a plate consisting of similar materials throughout but having a fine deposit on its face section followed by a relatively coarse deposit for the backing or body section, or may conl sist of dissimilar materials such as, for example, the application of a harder and tou her material for the working face. In 0t, er words, a-printing plate comprising substantially a body portion of sprayed metal having open, porous, non-homogeneous characteristics is useful for my purpose.

In the accompanying drawings- Fig. 1 is a cross sectional new of a printing plate made by my method wherein a fine face V, W bymeansof a spray or by a subsequent electrolytic deposit.

Fig. 3 is a perspective view showmg the apparatus and plate in position for curvlng.

This apparatus is indicated as an entirety by B which is supported on a suitable base. This curvin apparatus consists essentially of a heated ase indicated as an entirety S',

having a polished curved base section 18' suitabl heated as conventionally shown by the coc 21 for the admission of a suitable heating medium. Pressure is applied by means of the screw arrangement 22 operating against the concave polished platen 23 against the face of the printing plate 18, the back of the printing plate being indicated by 20. Su1table cooling facilities are again provided by means of the opening to the cored out section of the base S wherein 24 indicates the inlet for a cooling medium and 25 an opening for a suitable outlet. The plate is placed face up upon the heated platen S until the desired temperature is reached. This for foundry type metal will be about 400 to 500 F. It

will be found that the plate when sufliciently heated will have assumed its curved form and that a slight pressure from the platen 23 will cause the plate to assume the curve pro-" vided for by the concave section 23 and con vex section 18. For some purposes a suitable blanket may be interposed between the back of the plate 20 and the convex section 18' in order that irregularities may be taken up. By taking up these irregularities against the face of the platen 23, the necessary regularities or irregularities required in a suitable printing plate may be introduced at the same time that the plate is being curved.

The plate is preferably set to rigidity by the introduction of a suitable cooling medium such as water circulating through the openings 24. and 25. i It will be noted that the concave face portion 23 is preferhave found that it is preferable to have this portion of the ap paratus relatively cold in order that the printing face may not become marred or mush roomed sho d the plate become'too thermothis process, I ma produce intaglio plates by the use of suitab e originals or by means of ordinary expedients such as, for example, in-

version.

While I have herein shown and described certain preferred embodiments of my invention, I wish it to be understood that I do not confine myself to all of theprecise details herein set forth, as modifications and variav tions may be made without departing from the spirit of the invention-or exceeding the scope of the appended claims.

What I claim is,- -1. The herein described method of producing a curved printing'plate which consists in forming-a relatively flat plate body of sprayed metallic particles and providing the samewith a printing face and then heating such plate below its melting point and curving the heated plate overa suitable form to a predetermined shape.

2. The herein described method of producing a curved printing plate which consists in forming a relatively flat plate body of sprayedmetalhc particles and providing the same with a printing face, heating the plate below its melting point, and curving the heated plate over a suitable form to a desired dimension to obtain a predetermined curve while maintaining the dimensions of the printing face of .the plate.

3. The herein described method ofproducing a curved printing plate which consists in forming a relatively non-homogeneous plate body of sprayed metallic particles and providing the same with a printing face, then heating such plate and curving the same over a suitable form to a predetermined shape, and then cooling. the plate.

4. The herein described method of producing a curved printing plate which consists in forming a relatively flat, porous, nonhomogeneous plate body of sprayed metallic particles and providing the same with a printing face, then heating the plate and curving the heated plate in contact with a suitable form, and then cooling the plate.

5. The herein described method of producing a curved printing plate which consists in forming a plate body, composed of a section of coarse sprayed metallic particles and a section of fine sprayed metallic particles and providing said plate body with a printing face, then heating the plate below its melting point and curving the plate while so heated over a suitable form, and then cooling the plate.

6. The herein described method of producing a curved printing plate which consists in forming a relatively fiat, porous, non printing face, and then subsequently cooling homogeneous plate body of sprayed metallic said plate.

particles and providing said plate with a Signed at Philadelphia in the county of 10 printing face, then heating the plate and Philadelphia and State of Pennsylvania this curving the same while heated over a suitable 5th .day of November, A. D. 1926. form while producing at the same time dey sired regularities and irregularities in the V 1 EMIL E. NOVOTNY. 

